1883, "fastidious man," New York City slang of unknown origin. The vogue word of 1883, originally used in reference to the devotees of the "aesthetic" craze, later applied to city slickers, especially Easterners vacationing in the West (dude ranch first recorded 1921). Surfer slang application to any male is first recorded c.1970.
A dapper man, esp one who is ostentatiously dressed; dandy •In earliest use, to quote an 1891 source, a dude was ''not a dandy; there is nothing gallant or dashing about him. He is soberness itself; he is as respectable as an undertaker. Yet your real dude is irresistibly comic'' (1883+)
A guest at a Western or Western-style ranch (1883+)
A man; fellow; cat, guy: I'm sittin' in the bus stop, just me an' these other three dudes(1918+)
[origin unknown; perhaps an invented word]
The Dictionary of American Slang, Fourth Edition by Barbara Ann Kipfer, PhD. and Robert L. Chapman, Ph.D. Copyright (C) 2007 by HarperCollins Publishers. Cite This Source